Temperature responses to step changes in the load current of power transformers

被引：41

作者：

Nordman, H ^{[1
]}

Rafsback, N

Susa, D

机构：

[1] ABB Oy, FIN-65101 Vaasa, Finland

[2] Helsinki Univ Technol, FIN-02015 Helsinki, Finland

来源：

IEEE TRANSACTIONS ON POWER DELIVERY | 2003年 / 18卷 / 04期

关键词：

eddy losses; leakage flux; overloading; power transformer; winding hot-spot;

D O I：

10.1109/TPWRD.2003.817516

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Comprehensive load/thermal testing was performed on a 400/400/125-MVA, ONAF-cooled transformer. It was shown that the local hot-spots in the windings, core and structural parts rise much faster at load increase than what an exponential function based on the time constant of top oil would predict. This paper analyzes these fast rises more in detail for hot-spots in windings, core, yoke clamps, and tie plates. An alternative mathematical model of the winding hot-spot response is presented. Different cooling modes, like ONAF and OFAF, are dealt with. Also, different modes of. oil circulation through the windings, in horizontal (zig-zag) or axial cooling ducts, are compared. The results are verified by fiber optic installations and tests on several large power transformers in the range of 250-650 MVA. Hot-spot responses predicted by the IEEE Loading Guide, Annex G, are also compared to measured values.

引用

页码：1110 / 1117

页数：8